I'm attempting to source valves for the FNM from Brazil. These exactly fit the 102 head in all regards, except they have a reduced diameter upper stem of 9mm, allowing the use of late-model valve shims. As an alternative, does anyone know of valves from other makes (BMW etc?) that might do the job for us?
I'm also looking for retainers and keepers for the FNM valves for obvious reasons, but suspect these could be found domestically with enough research. I'm working on that as well.
Jay has remarked on valve changes as an option to finding the non-findable 10mm shims. Jay - can you re-educate us on your discoveries?
The valves in my FNM head were 10mm stem with 9mm top. I used 105/115 shims to adjust the clearance. We used standard 102 valve guides to fit the 10mm stem.
It is entirely possible that earlier Rio/FNM units had 10mm stems all the way up, but mine had the reduced shank at the top. I saw a similar valve at the machine shop with smaller top than stem, but we have not yet done any measuring of the head, length, etc.
This is the 3rd time I have answered the same question. How am I not being clear? The FNM valve a) has a 10mm stem that fits the standard 102 valve guides, b) has a 9 mm reduced upper stem that accepts the 105 shim. I did not do the valve grinding myself, so cannot attest whether the angle of the valves is the same as the 102, but the diameter is the same, so should fit the 102 valve seats so long as the grind angle matches.
Thanks DP3, just wanted to be sure.
I have a spare head,that I was thinking of converting to 9mm steams, 105 speck. As Jay recomend
But the solution with the Rio valves, is a nicer solution, I think.
Please keep us informed in you search